Fluid biased flow control means



Oct. 27, 1970 s. A. GRUBER 3,5365432 FLUID BIASED FLOW CONTROL MEANSFiled March 26, 1968 2 Sheets-Sheet i STEP/96M A. awuase 4 Tram/5 v:

Oct. 27, 1970 s, GRUBER v a 3,536,432

FLUID BIASED FLOW CONTROL MEANS Filed March 26, 1968 z s heetsfsh eet 2n s, m m 9 7' /n 6 Q r- N N) h 03 5 13" m (G 9 r a 0o '0 3 w [L l lINVENTOR'. Sni /04. amuse? United States Patent 3,536,432 FLUID BIASEDFLOW CONTROL MEANS Stephen A. Gruber, 1352 E. 82nd St., Cleveland, Ohio44103 Continuation-impart of application Ser. No. 515,924,

Dec. 23, 1965. This application Mar. 26, 1968,

Ser. No. 716,168 The portion of the term of the patent subsequent toApr. 9, 1985, has been disclaimed,

Int. Cl. F16k 31/50 US. Cl. 251-175 4 Claims ABSTRACT OF THE DISCLOSUREA flow control, on-ofif valve which is biased in its closed position byfluid pressure in the line that is closed by the valve. The valve has apiston slidably mounted in a cylinder and having one end projecting outof the cylinder. The projecting end of the piston has a sealing meanswhich is adapted to engage and seal an outlet opening in the valve asthe cylinder and its piston are moved toward the opening. A passagewayis provided through the piston so that fluid pressure is exerted on thepiston face within the cylinder to hold the piston and its sealing meanson the outlet opening. A detent is provided in the cylinder to limit theoutward travel of the piston from the cylinder and to lift the pistonfrom the outlet opening to open the valve. A stop member is provided onthe valve body to limit the travel of the cylinder toward the outletopening to prevent the cylinder from exerting mechanical force in thepiston which, in turn, would cause excessive sealing pressure betweenthe seal and the valve seat.

This application is a continuation-in-part of copending application Ser.No. 515,924, filed Dec. 23, 1965, now Pat. No. 3,377,048.

This invention relates to flow control means and, more particularly, toa closure member for selectively opening and closing the outlet openingof a fluid flow control valve.

According to this invention, a valve closure member may be advancedtoward the outlet opening of a valve casing so that the closure membermay engage the valve seat without the usual scoring between the valveseat and the valve closure member. The closure member according to thisinvention may comprise a piston which is mounted within a cylinder sothat the piston has a preselected stroke within the cylinder. Thecylinder may be advanced or retracted toward the outlet opening of thevalve along an axis normal to the outlet opening. Means are provided tosupply line pressure in the cylinder behind the piston so that thepiston is urged toward the outlet opening when the closure member isbrought into engagement with the valve seat and so that the outletopening will remain closed as the cylinder moves along a path which issubstantially equal in length to the stroke of the piston. Thus, asubstantially constant pressure is exerted by the closure member on thevalve seat even though the cylinder is advanced past its sealingposition with respect to the outlet opening of the valve. Such furthertravel is limited, however, by a stop member on the valve body so thatthe closure member is not mechanically forced on the valve seat. Thisarrangement minimizes unnecessary pressure and surface-to-surfacescoring between the closure member and its valve seat as the closuremember is advanced past its effective sealing position.

It is therefore a principal object of the present invention to providean improved closure member and closure member advancing means for avalve which effectively seals the outlet opening of the valve whileminimizing unnecessary scoring and eliminating surface-to-surfacefrictional contact between the closure member and its valve seat.

It is a further object of this invention to provide an improved closuremember and closure member advancing means which may be included instandard valves without ex ensive modifications to such valves.

These and other objects and advantages of the invention will becomeapparent from the following description and accompanying drawings.

In the drawings:

FIG. 1 is a longitudinal, cross sectional view, with portions brokenaway for clarity, of a valve embodying the present invention, showingthe valve in an open condition; and

FIG. 2 is a longitudinal, cross sectional view, with portions brokenaway for clarity, of a valve embodying the present invention, showingthe valve in a closed condition.

Referring now to the drawings, a valve body 10 is illustrated. The body10 may comprise a faucet-type valve or any other type valve employed forcontrolling fluid flow. The body 10 includes a spigot 11, a threadedinlet portion 12 having an inlet passageway 13 therein, a stem housing14, and an inlet opening 15 which is defined by an annular valve seat16.

A closure member 17 is provided ad the closure member 17 comprises apiston 18 having an enlarged cylindrical end portion 19 which isslidably mounted in a cylinder 20. A detent means which comprises acylindrical ring 21 is fixed within the lower end of the cylinder 20 andis retained therein by an interference fit between its outer side walland the side wall of the cylinder. The inner surface of the ring 21slidably receives a reduced cylindrical lower end portion 22 of thepiston 18. An upper edge 23 of the ring 21 serves as an abutment for anannular shoulder 24 which is formed at the juncture between the portions19 and 22 of the cylinder 18 to thereby limit and define the stroke ofthe piston Within the cylinder 20.

The lower end of the portion 22 of the piston 18 is provided with asealing member 25 which may comprise a neoprene washer adapted to engagethe annular valve seat 16. The sealing member 25 is attached to thelower end of the piston 18 by a screw 26. The screw 26 engages athreaded counterbore 27 in the piston 18. The screw 26 is provided witha central passageway 28 which communicates with an axial bore 29 in thepiston 18.

The upper end of the piston 18 is provided with a piston seal 30, whichmay be Teflon or some other suitable sealing material. The seal 30 isfixed to the top of the piston 18 by a screw 31 which engages a threadedcounterbore 32 in the piston 18. The screw 31 is provided with a centralpassageway 33 which communicates with the axial bore 29 in the piston18.

The cylinder 20 is defined by an enlarged threaded portion 34 of a valvestem 35. The portion 34 is threadedly received by threads 36 formed inthe portion 14 of the body 10. The valve stem 35 is guided by a bonnet37 which is threaded onto the upper end of the portion 14- and asuitable seal 38 is provided between the bonnet 37 and the stem 35.

The valve closure member 17 may be advanced toward the valve seat 16 bythreading the portion 34 into the body 10. Since a passageway isprovided through the piston 18, the fiuid pressure exerted on thesealing member 25 equals the pressure in the cylinder behind the piston18. The piston 18, therefore, tends to remain in the positionillustrated in FIG. 1 as the valve stem 35 and its enlarged portion 34are moved downwardly.

When the sealing member engages the valve seat 16 to thereby close theoutlet opening 15, the force exerted by the fluid in the cylinder 20above the piston 18 exceeds the force exerted on the sealing member 25which is exposed to the outlet opening 15, since the face area of thepiston 18 exposed to the pressure in the cylinder 20 is greater than theface area of the sealing member 25 which is exposed to the substantiallyequal line pressure. The net force is, therefore, in a downwarddirection as viewed in the drawings to effect a seal at the outletopening 15.

If, after the sealing member 25 establishes its sealing contact with thevalve seat 16, the valve stem is further rotated, such rotation will notaffect the established force between the sealing member 25 and its seat16. Any further advancement of the valve stem and its threaded portion34 merely causes the cylinder 20 to slide downwardly relative to thepiston 18 and such sliding motion does not impart any substantial axialforce to the piston 18. Thus, the sealing member 25 may be seated with apredetermined force (depending upon the relative cross sectional areasof the piston 20 and the outlet opening 15 and the line pressure)without any significant sliding contact between the sealing element 25and its valve seat 16. In the embodiment illustrated, such overtravel ofthe valve stem ensures that an effective seal has been established. Invalves that do not employ threads to impart axial movement of the valvestem (such as valves employing solenoid and cam actuated valve stems)the overtravel permitted by the arrangement according to this inventionensures an effective seal and minimizes the need for a precisepredetermination of valve stem travel.

During such overtravel, however, an end face of the piston 20 approachesthe upper face of the screw 31. If the face 40 were permitted to applypressure to the screw 31, I

this pressure would be transmitted to the sealing member 25 and causeunnecessary and excessive pressure between the sealing member 25 and theannular valve seat 16. Such excessive pressure may cause premature wearof the sealing member 25 and/or the valve seat 16. Furthermore, valvespreviously referred to that do not employ threads to impart axialmovement of the valve stem may have excessive overtravel, which wouldapply unnecessary mechanical pressure to the sealing member and thevalve seat.

-In order to prevent such unnecessary overtravel, a blocking means isprovided between the valve body and the cylinder to stop the movement ofthe cylinder prior to engagement of the piston by the face 40 of thecylinder. In the illustrated embodiment, the blocking means includes anannular shoulder 41 which is adapted to block an end face 42 of thecylinder 20 after the sealing member 25 engages the valve seat 16. Aftersuch engagement, the face 42 is spaced from the shoulder 41 a distancewhich is less than the distance between the piston face 40 and the screw31 so that the face 42 will engage the shoulder 41 prior to engagementof the screw 31 by the face 40.

It should be appreciated that unnecessary overtravel of the cylinder 20may be blocked by other means. For example, the cylinder 20 may beaxially lengthened so that the face 42 will engage a bottom portion 43of the valve body which surrounds the annular valve seat 16. Moreover,such a blocking means may be eifected by providing an enlarged detentportion on the valve stem 35, which will engage the bonnet 37.

The sealing element 15 may be unseated by unscrewing the valve stem 35relative to the body 10 so that the top portion 23 of the ring 21engages the annular shoulder 23 of the piston 18. Further rotation ofthe valve stem 35 lifts the sealing element 25 from its seat 16.

In light of the above teachings, many modifications and variations ofthe invention will become apparent to those skilled in the art. It is tobe understood, therefore, that within the scope of the appended claims,the invention may be practiced otherwise than as specifically disclosed.

What is claimed is:

1. In a fluid flow control valve having an outlet opening comprising avalve seat and a closure member for selectively opening and closing theoutlet opening, means for moving said closure member along an axisnormal to the outlet opening, said means comprising a cylinder, saidclosure member comprising a piston having one end slidably mounted insaid cylinder and having sealing means at its opposite end adapted toengage and seal said outlet opening, detent means carried by saidcylinder limiting the travel of said piston out of said cylinder byengaging a portion of said piston so that the piston has a preselectedstroke within said cylinder, means defining an opening through saidpiston so that the fluid pressure exerted on the piston face within saidcylinder corresponds to the pressure exerted on the sealing end of thepiston, said piston face having a greater area than the area defined bysaid outlet opening so that the sealing means is retained in its closedposition by the force exerted on the piston face, so that the pistonoutlet opening will remain closed as the cylinder moves along a pathsubstantially equal in length to the stroke of the piston, and so thatthe sealing means may be moved to an open position when said detentmeans engages said portion of the piston, in combination therewith theimprovement comprising blocking means on said valve body for limitingfurther movement of said cylinder relative to the piston after saidsealing means is in its closed position and before engagement of thepiston face in the cylinder by the cylinder to prevent the applicationof additional sealing force between said sealing means and said outletopening.

2. The improvement according to claim 1 wherein said cylinder is definedby a valve stem which threadedly engages a portion of the valve and ismoved along said axis by said threaded engagement. l

3. The improvement according to claim 1 wherein said detent meanscomprises a cylindrical ring fixed within said cylinder and wherein saidpiston has a relatively large upper portion slidingly engaging thecylinder wall, a relatively small lower portion slidingly engaging saidring, and has an annular shoulder portion between said upper and lowerportions which engages an upper end of the ring.

4. In a fluid flow control valve having an outlet opening comprising avalve seat and a closure member for selectively opening and closing theoutlet opening, means for moving said closure member along an axisnormal to the outlet opening, said means comprising a cylinder, saidclosure member comprising a piston having one end slidably mounted insaid cylinder and having sealing means at its opposite end adapted toengage and seal said outlet opening, detent means carried by saidcylinder limiting the travel of said piston out of said cylinder byengaging a portion 'of said piston so that the piston has a preselectedstroke within said cylinder, means defining an opening through saidpiston so that the fluid pressure exerted on the piston face within saidcylinder corresponds to the pressure exerted on the sealing end of thepiston, said piston face having a greater area than the area defined bysaid outlet opening so that the sealing means is retained in its closedposition by the force exerted on the piston face, so that the pistonoutlet opening will remain closed as the cylinder moves along a pathsubstantially equal in length to the stroke of the piston, andReferences Cited so that the sealing means may be moved to an open posi-UNITED STATES PATENTS tion when said detent means engages said portionof the 2 857 130 10/1958 Brisbane 251 175 piston, in combinationtherewith the improvement com- 2886283 5/1959 N ath o prising blockingmeans on said valve body for limiting 5 3033515 5/1962 251 175 movementof the cylinder after said sealing means en- 3:043554 7/1962 La Garza251 175 gages and seals said outlet opening, said blocking means,3377:0455 4/1963 Gruber 251 175 after such engagement, being spaced froma portion of the cylinder to be blocked a distance which is less thanCLARENCE GORDON, Primary Examiner the distance between said piston faceand an end face of 19 CL the cylinder opposite said piston face.251-275, 284

